I hear this all the time, and often from writers, but it never sounds right. I found myself using it in something I was writing.
For example: "Just because I stopped eating doesn't mean I'm full." Just the "just because A, doesn't mean B" sentence structure in general. Is it grammatically correct? If not, why not?
Best Answer
This construction has been explored over on English Language & Usage, and there's an interesting and more thorough treatment here.
The bottom line is there's nothing "grammatically incorrect" about "Just because X doesn't mean Y", but there are definitely some peculiarities. Not least that we're happier with "mean", rather than alternatives such as "imply", "prove", "establish", "reflect", etc., which (grammatically speaking) are no different.
Having said that, this is more a question of style than grammar. But in that context it's worth noting that ELU has had at least three questions about the usage, so obviously people feel it's at least "slightly odd".
I think it's generally perceived as an idiomatic usage more appropriate to informal speech than formal writing. I personally don't think there's any real justification for that perception — but since it exists, the careful writer should take it into account. In short...